Dryer-added fabric softening products provide a convenient way for a consumer to provide fabric conditioning benefits to laundry.
Generally, there are two main types of dryer-added fabric softening products, namely, single use products and multiple-use products. Single use products, most commonly in the sheet form coated with a fabric softening composition, call for adding a single sheet into an automatic clothes dryer containing a wet laundry load, at the beginning of the drying cycle. Examples of these types of products are disclosed in U.S. Pat. Nos. 3,442,692 and 3,686,025.
Multiple use fabric softening products are placed in the interior of the dryer to release the fabric conditioning component to successive laundry loads. Each multiple-use product lasts many drying cycles and thus provides a better convenience to the consumer than a single use product. Examples of multiple-use products include those described in U.S. Pat. No. 3,676,199 and US 2003/0192197 A1.
A problem facing such multiple use products, particularly those products having uses over 20, or 30, or more cycles, is the potential for fabric staining on dark heavy laundry. The addition of perfume to these products may also exacerbate the problem. Without wishing to be bound by theory, the fabric staining usually results earlier in the product's life cycle (e.g., the first cycle) when the product is less dense opposed to later on when the bar becomes “cured” having gone through multiple dryer cycles. There is a need to provide a multiple use fabric softening product that minimizing fabric staining (particularly in the first cycle), yet provides effective fabric softening and/or freshening benefits throughout the course of the product life span (e.g., over 40 or more cycles).